Just under 2000 households are without power in Auckland, Vector said, with 913 homes restored overnight - down from a total 16,900 at the height of the storm.
"Vector crews restored small pockets of customers left off from the storm and also dealt with fresh outages overnight in Torbay, Woodlands, Oratia, and Titirangi caused by the continual blustery high winds," a spokeswoman said.
"The customers still off are in areas where access is challenging or where the network damage requires extensive work. Fresh crews will be out in numbers today to take over from the night crews."
In the Far North 7500 homes are still without power this morning, despite 3500 being restored last night.
"Two thirds of those off supply are in the northern part of the region, where the damage has been more extensive," a Top Energy spokesman said.
"Crews will be back out at daylight, but continue to experience very heavy rain and high winds across the region."
The worst affected areas are in Pukenui, Awanui, Te Kao, Te Hapua, Mahiniapua, Peria and Towai.
The company also warned customers that some may be facing a third night without power.
"We're gutted that, by the time supplies are fully restored, a significant chunk of the Far North will end up having been without power for two, possibly even three nights," said Top Energy CEO Russell Shaw.
"We lost 75 per cent of supply to the Far North supplied from Kaitaia and 25 per cent to the Mid North supplied from Kaikohe."
Repairs are being hampered by significant access issues due to downed trees and flooding.
"Our lines staff have had to chop trees off roads just so we can get to the lines," Mr Shaw said.
The storm was the most severe event the company had experienced for at least a decade, he said, and the scale of the damage to the network, across the entire region, was "immense".
This included damage to poles and other structures.
"Sturdy concrete electricity poles have been blown down and even snapped, and large 50-60 year-old trees have been blown down across lines and access roads. Winds gusting up to 160 km/hr have ripped lines out of the cross-arms on electricity poles."
The structural damage would increase repair time, Mr Shaw said.
Meanwhile, power has been restored to all customers in Christchurch who experienced an outage due to a fault last night, Orion said.
The fault occurred on a high voltage line that runs from Islington to Papanui, cutting power to around 30,000 customers in north and north-west Christchurch at around 9.30pm.
The cause of the outage will not be known until the high voltage line is able to be examined in the daylight, Orion said.
Meanwhile, insurers have paid out nearly $77 million on claims for storm damage in the first half of this year, the Insurance Council of New Zealand says. The final insurance cost of damage from the storm that hit Canterbury and the lower North Island on March 4 and 5 was $22.5 million, taking the total storm-related insured payouts for the first six months of the year to $76.9 million, chief executive Tim Grafton said.
Insurers settled more than 4000 claims for the Canterbury storm paying out $21.6 million, including $15.2 million in domestic claims.
